Porosity determination method of lithium ion battery pole piece

Abstract

The invention discloses a porosity measuring method of a lithium ion battery pole piece, and the method comprises the following steps: taking an object to be measured, and measuring the volume V0 of the object to be measured; injecting a certain amount of inert gas into a sample pool of the true density instrument; putting an object to be measured into a sample pool of the true density instrument,and performing measuring to obtain a real volume V; and performing calculating to obtain the porosity of the pole piece. According to the technical scheme, based on the Boolean law of inert gas undercertain conditions, the true density of a sample is accurately measured by virtue of a true density instrument, so that the true density is obtained, and the method is used for measuring the porosityof positive and negative pole pieces in the lithium ion battery, blocky regular solids and diaphragms of positive and negative pole materials and other powder or solids with any apparent volume known; the invention provides a determination method which is safe, non-toxic, simple, convenient, effective and low in test cost in the test process.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a method for measuring the porosity of pole pieces of lithium-ion batteries. Background technique [0002] According to data, in the production process of lithium-ion batteries, the raw materials undergo slurry preparation, coating, pole piece rolling, slitting, drying and other processes, and the porosity of the pole piece will be significantly different from that of the raw material. The porosity properties are not indicative of the porosity of the final pole piece. The compaction density of the pole piece after the rolling process is increased, and the volumetric energy density and gravimetric energy density of the electrode are also increased accordingly. However, if the pressure is too high during the rolling process, the porosity of the pole piece will decrease, making it difficult for the electrolyte to penetrate into the inside of the pole piece, thereby re...

AI Technical Summary

Problems solved by technology

The above technical solution ignores the enlargement of the gap caused by the volume expansion of the pole piece during the soaking process, and also ignores t

Images